1. Field of the Invention
This invention relates to a lamp that indicates the status of an electrically-powered load control system and that, more particularly, indicates whether the power is off or on and whether the system is receiving a control signal.
2. Description of the Related Art
It is generally important to know whether or not power is being provided to a controlled electrical load, and pilot lamps have long been used for that purpose. Indicator lamps that provide additional information have also been disclosed.
U.S. Pat. No. 3,873,979, issued Mar. 25, 1975, to M. G. Craford et al., discloses a luminescent indicator that employs two solid state devices which emit different colors of light. The colors indicate the (changing) status of a condition being monitored. In different embodiments, the color change is either discrete--only one device on at any time--or continuous--with a gradual color change corresponding to the changing condition. In another embodiment, the change in status can cause the two lamps (which may be the same color) to flash alternately rather than be on continuously.
U.S. Pat. No. 4,388,589, issued June 14, 1983, to B. P. Molldren, Jr., discloses a system that includes a plurality of lamps of different colors. The system is designed so that a DC level is represented by a color. As the level changes the color changes.
U.S. Pat. No. 4,678,925, issued July 7, 1987, to D. Grocke, discloses an illuminating system for a motor vehicle that provides dim dashboard illumination when the vehicle's headlamps are on low beam and bright dashboard illumination when the headlamps are on high beam.
Remotely controlled electrical devices are well known, and wireless television controllers are quite common. In a remotely-controlled TV sold under the MGA label, an indicator lamp blinks when the TV is being remotely controlled, such as when the volume is being raised or lowered or the channels are being scanned.